In recent years, safety performance of automobiles has dramatically improved. In order to avoid a collision with a preceding vehicle, for example, a safety system is proposed in which the distance to the preceding vehicle and the velocity of the preceding vehicle are detected and a brake automatically engages in an abnormal approach to the preceding vehicle. In such a system, the distance to the preceding vehicle and the like are measured using a laser radar or a camera. In general, the laser radar or the camera is arranged on the inner side of a windshield, and the measurements are performed by emitting infrared rays ahead. Therefore, a system using a laser radar requires a glass plate for a windshield that transmits light at a predetermined transmittance. It is said that a glass plate having a small thickness is generally suitable for such a glass plate for a windshield. That is, use of a glass plate having a large thickness involves a risk that an infrared transmittance that is suitable for the safety system cannot be achieved.
However, a reduction in thickness of a windshield causes a decrease in sound insulation performance, and thus there is a problem in that sound occurring outside a vehicle enters the interior of the vehicle, deteriorating the environment in the vehicle. In order to solve this problem, for example, Patent Literature 1 discloses a laminated glass for an automobile that maintains the sound insulation performance at a predetermined frequency while having a decreased surface density. This laminated glass includes a pair of glass sheets and a resin interlayer that is arranged between the glass sheets.